Field of the Invention and Description of the Prior Art
This invention is concerned with improvements in and relating to pharmaceutical compositions and, more particularly, relates to cardiotonic compositions containing as active ingredient, a cardiac glycoside derived from Digitalis purpurea or Digitalis lanata or a derivative thereof. For convenience, such materials will hereinafter be simply referred to as "cardiac glycosides".
Cardiac glycosides are widely used cardiotonic agents and are commonly formulated as tablets for oral administration. Of necessity, each tablet must contain a very small amount of the active ingredient, (e.g. 250 micrograms or less) since these particular active agents are administered in such very small doses, almost always less than 0.5 mg. The fact that each tablet has to contain so little of the active ingredient gives rise to problems in formulation and, in particular, makes it very difficult to insure perfect compounding of the tableting mix so that each tablet contains the same amount, within tolerable limits of the active ingredient (see for example, Thomas et al, The Lancet, Dec. 1, 1973, pp. 1267-8; Fraser et al, 5, Pharm. Pharmac., 1973, 25, pp 268-973; and Shaw et al, British Medical Journal, 1973, 4, pp 763-766).